BL - Cardiovascular System Flashcards Preview

ESA 1 SEMESTER 1 TK > BL - Cardiovascular System > Flashcards

Flashcards in BL - Cardiovascular System Deck (21)
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1
Q

What are the functions of the cardiovascular system?

A

Circulates and transports nutrients/O2/CO2/hormones/blood cells, fights disease, stabilises temperature and pH

2
Q

What is the difference between the pulmonary and systemic circulation?

A

Pulmonary travels through lungs where blood is oxygenated, systemic forms a loop through the rest of the body to provide oxygenated blood

3
Q

What is meant by the term “closed cardiovascular system”?

A

Blood never leaves the network of arteries, veins and capillaries.

4
Q

How much circulating blood does the average adult have?

A

5 litres, of which 2 is red cells and 3 is plasma.

5
Q

Where is our blood situated within the body?

A

65% in peripheral veins, 20% in heart and lungs, 10% in peripheral arteries, 5% in capillaries.

6
Q

What is “bridging” of an artery?

A

The compression of a segment of a coronary artery during systole, resulting in a narrowing that reverses during diastole.

7
Q

What is an “end artery”?

A

A terminal artery supplying all/most of the blood to a body part without significant collateral circulation - if occluded, there is insufficient blood supply to the dependant tissue.

8
Q

Give some examples of functional end arteries.

A

Coronary arteries, splenic artery, cerebral and renal arteries.

9
Q

Give an example of an absolute end artery.

A

The central artery to the retina.

10
Q

What is “collateral circulation”?

A

“Back-up” arteries that can take over function if an artery becomes broken/blocked.

11
Q

Where does the heart beat originate?

A

The sino-atrial node

12
Q

Why is there a pause between the contractions of the SAN and the AVN?

A

To ensure that the ventricles have time to fill up.

13
Q

What is fibrillation?

A

Rapid, irregular and unsynchronised contraction of muscle fibres.

14
Q

Does the pressure in the aorta rise or fall during systole?

A

It rises due to left ventricle contraction, then falls in diastole.

15
Q

What are the three layers of arteries and veins?

A

Tunica intima (next to lumen), tunica media, tunica adventitia

16
Q

Where is the commonest site to find an aneurysm?

A

Infrarenal abdominal aorta, due to elastin fibres being less well-distributed here

17
Q

How many layers of smooth muscle does the tunica media contain?

A

40 (this is a lot)

18
Q

What is the name given to arteries that supply blood to capillary beds?

A

Metarterioles

19
Q

What do pre-capillary sphincters control?

A

Flow of blood through the capillary bed

20
Q

What are pericytes?

A

Cells that are capable of dividing into muscle cells or fibroblasts

21
Q

Which veins have a well-defined muscular wall (an exception to the rule that veins have less muscle than arteries)?

A

Superficial veins of legs, to resist distension caused by gravity

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